U.S. Pat. No. 3,051,453 discloses a mixer which is composed of a linear array of mixing elements referred to as "multiflux mixing body". This multiflux mixing body, the cross section of which is square, has two channels which gradually narrow in the direction of flow up to the middle of the mixing body and then gradually expand in a plane rotated by 90.degree. after reaching the narrowest point. A medium flowing through the mixing body experiences a rearrangement in which the number of partial layers is doubled.
The multiflux mixing body can--from a geometrical point of view--be constructed of four wedge-shaped partial bodies and two triangular plates. In one embodiment, the wedges have the form of a halved cube which is halved along the diagonal of a face. In each case two of the wedges--the one rotated by 90.degree. with respect to the other--form a united partial body. The two plates form partition walls between the two channels of the mixing body. The partial bodies occupy a volume comprising 25 to 30% of the tube volume associated with the mixing body.
Analogous mixing bodies with four channels--so-called ISG mixing bodies (ISG=Interfacial Surface Generator)--are known (cf. H. Brunemann, G. John "Mischute und Druckverlust statischer Mischer mit verschiedenen Bauformen", Chemie-Ing.-Techn. 43 (1971) p. 348). The ISG mixing bodies have circular cross sections. In a mixer with ISG mixing bodies, eight partial layers are produced in a medium consisting of two components to be mixed.
The multiflux and ISG mixing bodies require a relatively large amount of material for their construction, and take up 25 to 30% of the tube volume. The lengths of the mixing bodies in the direction of flow are relatively large, and are approximately of the same size as the tube diameter.